Topical formulations for the prevention of sexually transmitted disease and methods of producing the same

ABSTRACT

The present invention is directed towards various topical protective formulations which may be used as an adjunct in preventing the spread of a broad range of sexually transmitted diseases. The product is intended to be used as a topical lotion, cream, emulsion, or the like. The film forming excipients and active ingredients in the following formulations have demonstrated unique skin protective barrier properties with enhanced persistence that inhibits transmission of sexually transmitted diseases.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 13/778,211,filed Feb. 27, 2013, which is a continuation of application Ser. No.13/274,813, filed Oct. 17, 2011, now U.S. Pat. No. 8,409,556, whichissued on Apr. 2, 2013, which is a continuation of application Ser. No.12/038,283, filed Feb. 27, 2008, now U.S. Pat. No. 8,062,631, whichissued on Nov. 22, 2011, which is a continuation-in-part of applicationSer. No. 11/536,035, filed on Sep. 28, 2006, and now abandoned, thecontents of each of which are herein incorporated by reference.

FIELD OF THE INVENTION

This invention relates to topical protective formulations for use in theprevention of the spread of sexually transmitted diseases (STDs); andparticularly to unique topical formulations including a plurality offilm forming excipients which act in concert to provide a barrier tohelp inhibit the transmission of STDs.

BACKGROUND OF THE INVENTION

Sexually transmitted diseases (STDs) are a universal concern, effectingmillions of individuals and straining health care systems. More than 20different sexually transmitted diseases have been identified by themedical community and generally fall into two groups, includingbacterial types (e.g., gonorrhea, chlamydia and syphilis) and viraltypes (human immunodeficiency virus (HIV), human papilloma virus (HPV)and hepatitis). The numerous diseases affect men, women and children ofall backgrounds, races and economic classifications. Despite years ofresearch and educational programs, the transmission of sexuallytransmitted diseases remains a global health threat. Although specificmethods of transmission may vary depending on the disease-causingorganism, STDs are usually transmitted to the uninfected person throughinjured or exposed skin or mucous membranes during sexual contact.

Treatments may be available for some types of STDs (e.g. antibiotictreatment for gonorrhea or chlamydia). However, most people who sufferfrom these types of STDs are unaware that they have the disease andtherefore do not get the necessary treatment. Moreover, because of thesociological impact and generally negative stigma associated with thesediseases, people are reluctant to seek such treatments. The continuedemphasis on educating the population as to the use of “mechanicalbarriers” such as condoms has helped to decrease the morbidity of mostSTDs but more preventative methods need to be developed to prevent STDtransmission.

Chemical actives such as microbicides, antimicrobials, and spermicides,most notably, nonylphenoxypoly(ethyleneoxy)-ethanol (also referred to asnonoxynol-9) have been used in topical formulations to effectivelyreduce the rate of STD transmission, especially when used in conjunctionwith prophylactics. However, many of these chemical actives are harshand have been shown to induce local irritation, inflammation, andulcerations which might actually favor the transmission of STDs. Thus, aneed exists for topical formulations that do not cause irritation andwill help inhibit the spread of STDs, especially when used incombination with condoms, and thereby provide an additional degree ofprotection from contamination, should the condom become damaged.

PRIOR ART

Although there are numerous patents and publications directed toformulations containing chemical actives, such as, microbicides,antimicrobials, spermicides, and drug delivery carriers (liposomes,micelles), none of the known prior art teach formulations comprisingnon-irritating agents that provide a physical barrier to the permeationof pathogens.

U.S. Patent Application 2003/0143189 A1 to Askill et al., is directed toa method of treating skin lesions by forming a polymeric film over thelesions to inhibit proliferation of infectious agents in the lesions.These compositions also include one or more chemical agents incombination therewith.

U.S. Pat. No. 6,835,717 to Hildreth discloses a method of reducing therisk of a sexually transmitted pathogen by contacting a pathogen withinthe composition which consists of β-cyclodextrin.

U.S. Pat. No. 6,821,958 to Hershline discloses a method of preventingviral transmission using an alkylsulfate derivative of sulfated dextrinas a topical formulation.

U.S. Pat. No. 6,582,711 to Asmus et al., discloses an antimicrobialhydroalcoholic composition having a cationic polymeric thickener.

U.S. Pat. No. 6,355,235 to Cone et al., consists of an antibody capableof trapping sperm and a pharmaceutical carrier.

U.S. Pat. No. 6,328,991 to Myhling discloses a chemical composition toprevent the transmission of sexually transmitted diseases comprisingnonylphenoxpoly-(ethyleneoxy)-ethanol, benzalkonium chloride andpovidone iodine.

U.S. Pat. No. 5,439,685 to Augros is a composition of an agent activeagainst microorganisms responsible for sexually transmitted diseasestogether with a film forming agent such as dimethylpolysiloxane, andbenzalkonium chloride as a spermicidal.

U.S. Pat. No. 4,952,411 to Fox, Jr. et al., is a composition of silversulfadiazine, alone or in combination with chlorhexidine or sodiumdeoxycholate (antimicrobial and detergent).

SUMMARY OF THE INVENTION

The purpose of this invention is to provide non-irritating protectiveformulations to be used as an adjunct in preventing the spread of abroad range of sexually transmitted diseases. The products of thepresent invention can be formulated as a topical lotion, cream,solution, emulsion, or the like, and will be hereinafter referred to ascreams. The use of antimicrobial/antiviral active agents andfilm-forming excipients in the following formulations have demonstratedunique skin protective barrier properties with enhanced persistence thatinhibit “skin to skin” and “sore to sore” transmission of pathogens(e.g., viruses, bacteria, fungi, parasites, ectoparasites andmycoplasmas) linked to communicable diseases.

Skin protectant products are regulated under CFR 21 Part 347 “SkinProtectant Drug Products for Over the Counter Human Use”. The officialdescription of a skin protectant is “a drug product that temporarilyprotects injured or exposed skin or mucous membrane surfaces fromharmful or annoying stimuli, and may help provide relief to suchsurfaces.” These regulations cover applicable ingredients, as well aslabeling requirements for over the counter skin protectants. Activeingredients officially classified as skin protectants compositions aswell as certain combinations of these compositions are listed in the CFR21 Sec. 347.10, reproduced in Table 1 below. In accordance with theinstant invention, the phrase “a skin protectant composition provided ina skin protecting effective concentration” will be understood to meanany of the following ingredients within their designated range ofconcentrations:

TABLE 1 These include any of the following within the concentrationrange specified: Ingredient Concentration Allantoin 0.5 to 2.0% Aluminum hydroxide 0.15 to 5.0%  gel Calamine 1.0 to 25.0% Cocoa Butter50.0 to 100.0% Cod liver oil 5.0 to 13.56%(in accordance with Sec.347.20(a)(1) or (a)(2), provided the product is labeled so that thequantity used in a 24-hr period does not exceed 10,000 USP Units vitaminA and 400 USP Units cholecalciferol. Colloidal oatmeal 0.007 minimum;0.003 minimum in combination with mineral oil in accordance with Sec.347.20(a)(4). Dimethicone 1.0 to 30.0% Glycerin 20.0 to 45.0%  Hard fat50.0 to 100.0% Kaolin 4.0 to 20.0% Lanolin 12.5 to 50.0%  Mineral oil50.0 to 100.0%; 30.0 to 35.0% in combination with colloidal oatmeal inaccordance with Sec. 347.20(a)(4). Petrolatum 30.0 to 100.0% Topicalstarch 10.0 to 98.0%  White petrolatum 30.0 to 100.0% Zinc acetate 0.1to 2.0%  Zinc carbonate 0.2 to 2.0%  Zinc oxide 1.0 to 25.0%

It has been discovered that incorporation of at least one of theaforementioned skin protectants compositions listed in Table 1 incombination with other film forming excipients, in particular,film-forming emollients (e.g., Cetostearyl alcohol, Cetyl alcohol),silicone-containing excipients/skin protectants (e.g.,polydimethylsiloxane derivatives of varying viscosities, utilized eithersingly or in combination, and marketed under names such as Dimethicone20 and Dimethicone 12500), emulsifying agents (e.g. selected fromCetearyl alcohol (a mixture of fatty alcohols, predominantly stearyl andcetyl alcohols, polyoxyethylene ethers of a mixture of high molecularmass saturated fatty acids (mainly cetyl alcohol and stearyl alcohol,having a number of ethylene oxide residues in the polyoxyethylene chain,e.g. 20, 12 or the like, and referred to as Ceteareth-20, Ceteareth-12,or the like, and/or mixtures thereof), humectants (e.g. glycerin andanhydrous lanolin) and chelating compounds (e.g. disodium edetate) in aformulation for topical application results in a product thattemporarily protects injured or exposed skin or mucous membrane surfacesfrom harmful or annoying stimuli, thereby preventing cross-contaminationof pathogenic microorganisms responsible for sexually transmitteddiseases (e.g., Herpes simplex virus type 1 and type 2 (HSV-1, HSV-2),human immunodeficiency virus (HIV), or the like) through skin or mucousmembrane surfaces. In addition to the hydrophobic, barrier-formingformulation, active agents that prevent bacterial or viral transmissionare also included. The novel formulation products of this invention arepersistent in that they form a film or barrier on healthy or evendamaged skin.

The hydrophobic portions of the instant formulations utilize acombination of film-forming excipients, including skin protectant(s)listed in Table 1, silicones and silicone derivatives or likeequivalents, and film-forming emollients. These ingredients aredispersed by the emulsifiers throughout the continuous aqueous phase.They liquify and spread over the skin as a result of exposure to bodyheat. This forms a physical hydrophobic layer which resides on the skinsurface (including mucosal membranes) and provides a barrier which wouldinhibit penetration of liquids and pathogens which are primarilyhydrophilic in nature. When used in combination with consistent andcareful use of condoms, the products of the present invention helpinhibit the spread of STDs and protect the skin from contaminationshould the condom become damaged.

Accordingly, it is an objective of the instant invention to teachvarious topical protective formulations to be used in preventing thespread of a broad range of sexually transmitted diseases.

Another objective of the present invention is to teach formulationswhich are condom compatible, meaning that they are latex friendly andprovide effective lubricity.

It is yet another objective of the instant invention to teach skinprotective formulations wherein contact with the skin results in theformation of a hydrophobic skin protective surface layer.

It is yet another objective of the instant invention to teach skinprotective formulations wherein contact with the skin results in theformation of a mechanical barrier skin protective surface layer.

It is yet another objective of the instant invention to teach skinprotective formulations wherein contact with the skin results in theformation of a hydrophobic skin protective surface layer containingantiviral/antimicrobial agents.

Yet another objective of the invention is to teach products formulatedas a lotion, cream, solution, emulsion, or other topically appliedproduct.

Other objects and advantages of this invention will become apparent fromthe following description, wherein are set forth, by way of illustrationand example, certain embodiments of this invention.

DETAILED DESCRIPTION OF THE INVENTION

Detailed embodiments of the instant invention are disclosed herein,however, it is to be understood that the disclosed embodiments aremerely exemplary of the invention, which may be embodied in variousforms. Therefore, specific functional and structural details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representation basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure.

Zinc oxide is an inert, non toxic chemical compound with the chemicalformula of ZnO. Zinc Oxide can be used as a skin barrier. When appliedto skin, Zinc Oxide acts as a mechanical barrier that physicallyexcludes isolates and prevents the skin from any contact with harmfulstimuli. Zinc Oxide is often used in creams or lotions and provides acontinuous barrier which also helps prevent the loss of activeingredients due to friction and rubbing. Because of its inert, non-toxiccharacteristics and general non-solubility in water, it can be appliedto skin as many times as may be needed. While zinc oxide is thepreferred skin protectant composition of the present invention, othersuitable skin protectant compositions and their amounts effective toprovide skin protection as listed in Table 1 above could be used herein(e.g., Dimethicone).

Glycerin (INCI name: Glycerin) is a non-irritating humectant and filmformer. It is also water soluble. Moreover, glycerin is compatible withlatex products and provides extended lubricity, which makes it a commonbase for many products designed for genital use.

Lanolin is a humectant isolated from wool-bearing animals such as sheep.It is a product of the sebaceous gland and consists mostly of a mixtureof cholesterol and the esters of several fatty acids. It has manycommercial uses, including within the medical and cosmetic industries.

Benzalkonium Chloride is a member of the quaternary ammonium compounds.These compounds are a group of ammonium salts in which organic radicalshave been substituted for all four hydrogens of the original ammoniumcation. Benzalkonium Chloride has been reported to be an effectiveanti-viral wetting agent in the prevention of transmission of viraldiseases such as HIV and herpes simplex virus. Benzalkonium Chloride isalso listed in the FDA Topical Antimicrobial Drug Products Monograph asa First Aid Antiseptic. Although the use of Benzalkonium Chloride ispreferred, it is contemplated that any other quaternary ammonium saltcompound could be used without departing from the scope of the presentinvention, such as CETRIMIDE (alkyltrimethylammonium bromide).

The phase “film-forming emollient” refers to any excipient suitable forcosmetic and pharmaceutical applications which forms a water-repellingfilm. According to a preferred, albeit non-limiting embodiment, thefilm-forming emollients are cetyl alcohol and cetostearyl alcohol. Cetylalcohol (IUPAC name of 1-hexadecanol) is a member of the alcohol classof compounds. It is a solid organic compound and belongs to a group offatty alcohols. In addition to its use as an emollient, it is often usedin the cosmetic industry as a surfactant in shampoos, emulsifiers orthickening agents in the manufacture of skin creams and lotions.Cetostearyl alcohol is a blend of cetyl alcohol and stearyl alcohol, twofatty alcohols derived from vegetable sources.

The phase “silicone-containing excipient” refers to any silicone orsilicone derivatives, including silicone-based skin protectants,suitable for cosmetic and pharmaceutical applications which acts as anemollient and forms a water-repelling film, including silicone oils. Inaddition to skin barriers, silicone and silicone oils are highlysubstantive on the skin. As a result of this property, silicon andsilicone oils are often used in topical formulations, such as creams andlotions, to improve the substantivity of active ingredients on the skin.

After applying the topical formulations to the skin and removingvolatile substances, the film formed as a result of using asilicone-containing excipient helps to maintain the active ingredient inclose contact with the skin and prevents the loss of the activeingredient by abrasion. The ability to form hydrophobic films which caneasily be applied and spread over skin accounts for high resistance towash-off and rub-off. Use of silicones in topical formulations overpetroleum-based products is more desirable because silicones do notexhibit the negative aesthetics of petroleum and, unlike petroleum, areknown to be compatible with the materials used to manufacture condoms.According to one non-limiting embodiment, Dimethicone (preferablyDimethicone 20 cSt and Dimethicone 12500 cSt) is preferred. Dimethiconeis a highly pure, non-volatile silicone fluid which is colorless andodorless. It can be used as a lubricant and emollient skin protectant.

Ceteareth-12 is part of a family with the INCI name of Ceteareth-n andrefers to polyoxyethylene ethers of a mixture of high molecular masssaturated fatty alcohols. The “n” indicates the average number ofethylene oxide residues in the polyoxyethylene chain. Ceteareth-12 is anon-toxic surfactant which is frequently used as an emulsifier in thecosmetic industry. The mixture of Cetearyl alcohol and Ceteareth-20(EMULGADE 1000NI, Cognis Corporation) is a non-ionic, self-emulsifyingbase commonly used in the production of oil/water creams and lotions.

Disodium Edetate, having the chemical name of disodium(ethylene-dinitrilo) tetra-acetate dihydrate, is also commonly known asthe disodium salt of EDTA. The chemical acts as a chelating compound bypreventing ingredients from binding to trace elements that may bepresent.

Excipients and antimicrobial/antiviral ingredients useful in forming theskin protective creams, according to the present invention are describedin the following non-limiting example.

Example 1

In formulating a batch of a skin protective cream according to theinvention, active ingredients and excipients useful in the manufactureof this product, a particularly effective product resulted wheningredients were utilized within the following approximate ranges:

ACTIVE INGREDIENTS/EXCIPIENT WT/WT % RANGES Water phase (1) DEIONIZEDWATER Q.S. (2) EDETATE DISODIUM 0.01-0.1  (3) BENZALKONIUM CHLORIDE0.01-0.25 (4) ZINC OXIDE 1.0-8.0 (5) GLYCERIN (USP)  2.0-10.0 Oil Phase(6) DIMETHICONE 20 10.0-20.0 (7) DIMETHICONE 12500  3.0-10.0 (8)CETEARYL ALCOHOL and/  6.0-10.0 or CETEARETH-20 (9) CETEARETH-12 0.5-3.0(10) ANYHDROUS LANOLIN 0.5-3.0 (11) CETOSTEARYL ALCHOHOL 1.0-5.0 (12)CETYL ALCOHOL 1.0-5.0

A preferred, albeit non-limiting procedure for manufacture of theformulation comprises the steps of:

Procedure:

1. Heat to 75° C.-Dimethicone 20⁻, Dimethicone 12500, Cetearyl Alcoholand Ceteareth-20 (available as EMULGADE 1000 NI from Cognis),Ceteareth-12 (available as (EUMULGIN B1 from Cognis), Anhydrous Lanolin,Cetostearyl alcohol and Cetyl alcohol. Allow the materials to melt.2. Dissolve Disodium Edetate in the deionized water (USP).

3. Add Benzalkonium Chloride to Step #2 4. Heat Step #3 to 75-78° C.

5. Disperse the Zinc Oxide in the Glycerin to form a homogeneousdispersion.6. With high speed mixing, slowly add the materials from Step #4 (Waterphase) to the materials from Step #1 (Oil phase). Initiate cooling.7. When at 60° C.; add the dispersion from Step #5 to the materials fromStep #6 (Emulsion).8. When at 50° C., reduce mixing speed.9. When at 40° C., further reduce the mixing speed.10. When at 25° C. stop mixing.

While not wishing to be bound to any particular theory, it is believedthat these film forming excipients and active ingredient form a neutraland hydrophobic layer barrier which is also believed to interact withthe skin thereby having a stabilizing effect upon the hydrophobic layer,which results in the enhanced persistence of the product. The use of asilicone-containing skin protectant, e.g. Dimethicone 20 and Dimethicone12500, or a like equivalent, acts in coordination with at least one ofthe skin protectants compositions as defined in CFR 21 Sec. 347.10, e.g.Zinc Oxide, or others from Table 1, excipients and the film-formingemollients, and melts when contacted with the heat of the body. This inturn forms a physical hydrophobic layer that provides a barrier whichappears to inhibit penetration of liquids and sexually transmittedpathogens (viral, bacterial) which are primarily hydrophilic in nature.This property helps protect the user from contamination due to sexualcontact with infected individuals.

It is to be understood that while a certain form of the invention isillustrated, it is not to be limited to the specific form or arrangementherein described and shown. It will be apparent to those skilled in theart that various changes may be made without departing from the scope ofthe invention and the invention is not to be considered limited to whatis shown and described in the specification and drawings/figures.

All patents and publications mentioned in this specification areindicative of the levels of those skilled in the art to which theinvention pertains. All patents and publications are herein incorporatedby reference to the same extent as if each individual publication wasspecifically and individually indicated to be incorporated by reference.It is to be understood that while a certain form of the invention isillustrated, it is not to be limited to the specific form or arrangementherein described and shown. It will be apparent to those skilled in theart that various changes may be made without departing from the scope ofthe invention and the invention is not to be considered limited to whatis shown and described in the specification. One skilled in the art willreadily appreciate that the present invention is well adapted to carryout the objectives and obtain the ends and advantages mentioned, as wellas those inherent therein. The excipients and related compoundsdescribed herein are presently representative of the preferredembodiments, are intended to be exemplary and are not intended aslimitations on the scope. Changes therein and other uses will occur tothose skilled in the art which are encompassed within the spirit of theinvention and are defined by the scope of the appended claims. Althoughthe invention has been described in connection with specific preferredembodiments, it should be understood that the invention as claimedshould not be unduly limited to such specific embodiments. Indeed,various modifications of the described modes for carrying out theinvention which are obvious to those skilled in the art are intended tobe within the scope of the following claims.

What is claimed is:
 1. An oil-in-water formulation for the prevention ofsexually transmitted diseases, characterized by enhanced skin protectiveproperties comprising in combination: (1) a skin protectant compositionprovided in a skin protecting effective concentration; (2) asilicone-based skin protectant composition provided in a skin protectingeffective concentration; (3) a humectant-excipient, in the range ofabout 0.5 to 15.0% wt/wt; (4) a non-ionic emulsifier in the range fromabout 0.5 to 15.0% w/w; (5) a chelating compound in the range from about0.1 to 0.01% w/w; (6) a quaternary ammonium salt in the range from about0.01 to 0.25% w/w; (7) a film-forming emollient in the range from about1.0 to 10.0% w/w; and (8) water; wherein contact with the skin resultsin the in situ formation of a skin protective barrier layer effective inpreventing transmission of sexually transmitted diseases.
 2. Theformulation of claim 1, wherein said emulsifier is cetearyl alcohol,ceteareth-20 or a mixture thereof.
 3. The formulation of claim 1,wherein said emulsifier is ceteareth-12.
 4. The formulation of claim 1,wherein said emulsifier is a mixture of cetearyl alcohol andceteareth-20 and co-emulsifier ceteareth-12.
 5. The formulation of claim1 wherein said skin protectant is zinc oxide.
 6. The formulation ofclaim 1 wherein said humectant-excipient is glycerin.
 7. The formulationof claim 1 wherein said humectant-excipient is anhydrous lanolin.
 8. Theformulation of claim 1 wherein said humectant-excipient is a combinationof glycerin and anhydrous lanolin.
 9. The formulation of claim 1 whereinsaid silicone-based skin protectant is dimethicone
 20. 10. Theformulation of claim 1 wherein said silicone-based skin protectant isdimethicone
 12500. 11. The formulation of claim 1 wherein saidsilicone-based skin protectant is a combination of dimethicone 20 anddimethicone
 12500. 12. The formulation of claim 1, wherein saidfilm-forming emollient is cetostearyl alcohol.
 13. The formulation ofclaim 1, wherein said film-forming emollient is cetyl alcohol.
 14. Theformulation of claim 1, wherein said film-forming emollient is acombination of cetostearyl alcohol and cetyl alcohol.
 15. Theformulation of claim 1, wherein said chelating compound is disodiumedetate.
 16. The formulation of claim 1, wherein said quaternaryammonium salt is benzalkonium chloride.
 17. The formulation of claim 1,wherein said quaternary ammonium salt is cetrimide.
 18. The formulationof claim 1, wherein said formulation is in the form of a cream.
 19. Theformulation of claim 1, wherein said formulation is in the form of alotion.
 20. An oil-in-water cream for the prevention of sexuallytransmitted diseases, characterized by enhanced skin protectiveproperties comprising in combination: (1) Dimethicone 20, in the rangeof 10.0 to 20.0% wt/wt; (2) Dimethicone 12500, in the range of 3.0-10.0%wt/wt; (3) Zinc oxide, in the range of 1.0 to 8.0% wt/wt; (4) a mixtureof Cetearyl alcohol and Ceteareth-20, in the range of 6.0 to 10.0%wt/wt; (5) Glycerin, in the range of 2.0 to 10.0% wt/wt; (6)Ceteareth-12, in the range of 0.5 to 3.0% wt/wt; (7) disodium edetate,in the range of 0.01 to 0.1% wt/wt; (8) Benzalkonium Chloride, in therange of 0.01 to 0.25% wt/wt; (9) Anhydrous lanolin, in the range of 0.5to 3.0% wt/wt; (10) Cetostearyl alcohol, in the range of 1.0 to 5.0%wt/wt; (11) Cetyl alcohol, in the range of 1.0 to 5.0% wt/wt; and (12) asufficient quantity of deionized water to form the cream; whereincontact with the skin results in the in situ formation of a skinprotective barrier layer.
 21. An oil-in-water cream for the preventionof sexually transmitted diseases, characterized by enhanced skinprotective properties comprising in combination: (1) Dimethicone 20, atabout 15.0% wt/wt; (2) Dimethicone 12500, at about 5.0% wt/wt; (3) Zincoxide, at about 2.0% wt/wt; (4) a mixture of Cetearyl alcohol andCeteareth-20, at about 8.0% wt/wt; (5) Glycerin, at about 5.0% wt/wt;(6) Ceteareth-12, at about 1.0% wt/wt; (7) disodium edetate, at about0.05% wt/wt; (8) Benzalkonium Chloride, at about 0.2% wt/wt; (9)Anhydrous lanolin, at about 1.0% wt/wt; (10) Cetostearyl alcohol, atabout 3.0% wt/wt; (11) Cetyl alcohol, at about 2.0% wt/wt; and (12) asufficient quantity of deionized water to form the cream; whereincontact with the skin results in the in situ formation of a skinprotective barrier layer.
 22. An oil-in-water cream for the preventionof sexually transmitted diseases, characterized by enhanced skinprotective properties comprising in combination: (1) Dimethicone 20, atabout 15.0% wt/wt; (2) Dimethicone 12500, at about 5.0% wt/wt; (3) Zincoxide, at about 5.0% wt/wt; (4) a mixture of Cetearyl alcohol andCeteareth-20, at about 7.0% wt/wt; (5) Glycerin, at about 8.0% wt/wt;(6) Ceteareth-12, at about 1.0% wt/wt; (7) disodium edetate, at about0.05% wt/wt; (8) Benzalkonium Chloride, at about 0.2% wt/wt; (9)Anhydrous lanolin, at about 1.0% wt/wt; (10) Cetostearyl alcohol, atabout 3.0% wt/wt; (11) Cetyl alcohol, at about 2.0% wt/wt; and (12) asufficient quantity of deionized water to form the cream; whereincontact with the skin results in the in situ formation of a skinprotective barrier layer.
 23. An oil-in-water formulation for theprevention of sexually transmitted diseases, characterized by enhancedskin protective properties comprising in combination the followingingredients in % w/w: a water phase including (1) DEIONIZED WATER (USP)in quantities sufficient to dissolve ingredients 2-5; (2) DISODIUMEDETATE 0.01-0.1  (3) BENZALKONIUM CHLORIDE 0.01-0.25 (4) ZINC OXIDE1.0-8.0 (5) GLYCERIN (USP)  2.0-10.0 and an oil phase including (6)DIMETHICONE 20 10.0-20.0 (7) DIMETHICONE 12500  3.0-10.0 (8) CETEARYLALCOHOL and/or CETEARETH-20  6.0-10.0 (9) CETEARETH-12 0.5-3.0 (10)ANYHDROUS LANOLIN 0.5-3.0 (11) CETOSTEARYL ALCHOHOL 1.0-5.0 (12) CETYLALCOHOL 1.0-5.0


24. A process for forming an oil-in-water cream comprising: a waterphase including (in % w/w) (1) Deionized Water (USP) in quantitiessufficient to incorporate therein ingredients 2-5; (2) Disodium Edetate0.01-0.1  (3) Benzalkonium Chloride 0.01-0.25 (4) Zinc Oxide 1.0-8.0 (5)Glycerin (USP)  2.0-10.0 and an oil phase including (in % w/w) (6)Dimethicone 20 10.0-20.0 (7) Dimethicone 12500  3.0-10.0 (8) CetearylAlcohol And/Or Ceteareth-20  6.0-10.0 (9) Ceteareth-12 0.5-3.0 (10)Anyhdrous Lanolin 0.5-3.0 (11) Cetostearyl Alcohol 1.0-5.0 (12) CetylAlcohol 1.0-5.0

wherein said oil-in-water cream is produced in accordance with thefollowing steps:
 1. heating to 75° C. Dimethicone 20, Dimethicone 12500,Cetearyl Alcohol, Ceteareth-20, Ceteareth-12, Anhydrous Lanolin,Cetostearyl Alcohol and Cetyl Alcohol to allow the materials to melt; 2.dissolving Disodium Edetate in the deionized water;
 3. AddingBenzalkonium Chloride to Step #2;
 4. Heating Step #3 to 75-78° C.; 5.Dispersing the Zinc Oxide in the Glycerin to form a homogeneousdispersion;
 6. With high speed mixing, slowly adding the materials fromStep #4 (Water phase) to the materials from Step #1 (Oil phase) andinitiating cooling;
 7. When at 60° C.; adding the dispersion from Step#5 to the materials from Step #6;
 8. When at 50° C., reduce mixingspeed;
 9. When at 40° C., further reduce the mixing speed;
 10. When at25° C. stop mixing.